Electrolytic detector cell with adjacent compartments



Jan. 7, 1964 WILSON .L- ELECTROLYTIC DETECTOR CELL WITH ADJACENTCOMPARTMENTS CONTAINING PROTECTIVE COMPOUND Filed Jan. 13, 1958 OXYGENSCAVENGING,

OXIDATION REDUCTION LOUIS WILSON BY zw fl A TYS.

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Patented Jan. 7, 198% Ficc 3,117,259 ELEQTRGLYTKQ DETECTQER CELL WITHADFJA- QENT MPART VIENTS QONTAHNENG PRQTEC- tZs'HvilGUND Louis Wiison,Havertown, Fa, assignor to United States oi America as represented bythe fiecretary of the Navy Fiicd Jan. 13, 1958, Ser. N 798,734 4-Giairns. (til. 311-231) (Granted under Titie 35, U5. (lode (1952), see.255) The invention described herein may be manufactured and used by orfor the Government of the United States of America without the paymentof any royalites thereon or therefor.

The invention relates to an electrolytic detector cell which is highlyresistent to the effects of oxygen gas that would normally diffusethrough the housing thereof. More particularly, this application isconcerned with a new and improved electrolytic detector cell having apinrality of diaphragms defining a pair of chambers dis osed about thedetector cells and filled with an oxygen getter compound.

In the electrolytic detector cells used prior to this invention, theactive chemical ions in solution were subject to poisoning by oxygendififusing into the detector solution through the relatively thindiaphragms of the cell from the ambient air. For example in an I -Isolution, oxygen ditfusing through the flexible diaphragm surroundingthe solution reacted with the I ion producing I3 ions, thereby alteringthe sensitivity of the detectOI.

Prior to this invention it was the practice to incorporate a plastic bagcontaining 0 scavenging compounds into the hydraulic housing of thedetector to prevent oxygen from diffusing into the detector. The plasticbag in effect became a hydraulic shunt with respect to the detectorinsofar as oxygen diffusion was concerned. However, the plastic bagmaterial had to be carefully selected in order to eliminatecompatibility problems between the detector hydraulic fluid and detectorcomponent parts. Furthermore, this method was but a temporary expedientand by no means eliminated all of the oxygen diffusion through thediaphragm.

A second method of combating the absorption of oxygen by theelectrolytic fiuid was to incorporate oxygen scavenging compoundsdirectly into the hydraulic detector fluid. This mode of combating isinefiective if the detector is to be stored for long periods because ofthe oxygen scavenging compounds are not completely inert with respect tothe other detector parts such as the rubber and dififerent emf metals.Thus, the oxygen scavenging compounds can be expected to becomedesensitized because of its reactivity with components of the cell.Furthermore, the thin diaphragms of the detector cell admit appreciablequantities of oxygen into the detector and the oxygen scavengingcompound is quickly depleted by chemical reaction with the oxygen.

Accordingly, it is one object of this invention to provide a new andimproved electrolytic detector cell of sensitivity which does not varyover long periods of storage.

Another object of this invention is the provision of a i new andimproved detector cell including an oxygen getter compound forpreventing deleterious O 'absorp tion into the housing containing theelectrolytic detector fluid.

Still another object of this invention is to provide a detector cellhaving a pair of O scavenging chambers adjacent to the electrolyticdetector compartment for preventing 0 diffusion through the diaphragm ofthat compartment and presenting no compatability problems with thecomponents of the cell.

A still further object is the provision in an electrolytic detector cellof a pair of chambers containing oxygen scavenging compounds disposedadjacent each of the diaphragms of the detector cell and hydraulicallycoupled thereto for transmitting pressure signals to the cell andeliminating the diffusion of oxygen into the cell.

These and many other objects will become more readily apparent when thedrawing is considered along with the attendant description.

Referring now to the drawing which shows in section one embodiment of myinvention, it is seen that the detector cell is composed of a housing 11having an apertured wall 12 interiorly thereof. Disposed within theaperture in wall 12 is an active electrode 13) which is connected by abiasing battery 14 to a meter 16. A pair of thin flexible diaphragrns 17are disposed at either end of the housing and together with wall 12define a pair of compartments 18 containing an oxidation-reductionelectrolytic detector solution such as an I3 I ion system. A pair ofelectrodes 19 are each disposed in the respective compartments and areexternally connected to the positive terminal of battery 14 via meter16.

The above described portion of this cell is old and known in the art. Itoperates upon the fiexure of diaphragms 17 to bring electrolyticsolution through the active orifice electrode 13 to produce an outputvoltage in the circuit between electrode 13 and an appropriate electrode19. A more complete description of the basic principles of this type ofcell is more fully described in a brochure entitled Solion-Principles ofElectrochemistry and Low-Power Electrochemical Devices, published by theUS. Naval Ordnance Laboratory in 1957 and currently available in revisedform as a publication having the same title as publication No. PB 131931of the US, Department of Commerce, Office of Technical Services. A pairof hollow members 21 are secured to the outer peripheral portion of theappropriate diaphragm 17. Each member 21 has an outer diaphragm 22secured thereto defining a pair of chambers 23, one on either side ofthe compartments 18. These outermost chambers 23 are filled with oxygengetter compound. Since the getter compounds are not in contact with theelectrolytic fluid, no compatability problems :are presented. The numberof oxygen getter compounds suitable for the purpose is extremely large.Nevertheless a few examples are given merely as an indication of theextent of the range of suitable compounds which optionally may beemployed; electrolytic solutions such as contained in the main chambersmay be used if it is desired, however if an electrolytic solutioncontaining an I -I system is disposed in chamber 23 it is necessary thata pair of polarizing electrodes be disposed within each chamber tomaintain the polarization of the ions, paint dryers such as the linseedoil series, castor oil either in pure form or mixed with an inertsolution is also suitable, the organo metallic compounds (Grignardseries), organic amino and (NH derivative series in pure or solvent formalso may serve as the getter compound. Lineoleate compounds and longchain fatty acid series have also been success fully used as the gettercompound. A Pyrogallate solution in alkaline form is another suitableoxygen scavenger.

Since the chambers 2,3 are completely filled, they serve not only toabsorb oxygen diffusing through the outer diaphragm 22 but provide anhydraulic connection between the outer diaphragm 22 and the innerdiaphragm 17 thereby transmitting any pressure or acoustic signals tothe electrolytic detector fluid in compartments 18. The wall of casing11 is suflicient ly thick to inhibit substantial oxygen difiusion intocompartments 18 while the outer chambers 23 filled with an oxygenscavenging compound prevent diifusion of oxygen through the relativelythin diaphragms 17. The difiusion oxygen reacts with the oxygenscavenging compound and is thereby absorbed by or reacts with saidcompound and is unavailable for diiiusion through diaphragm 17 into thechambers 18 containing the electrolyte solution. Thus, is provided adetector cell having a very stable sensitivity even over prolongedperiods of storage.

While I have described this invention with particularity with referenceto but one preferred embodiment thereof, it will be apparent to oneskilled in the art after reading and understanding the above descriptionthat it is by no means so limited. Accordingly, the example givenhereinabove is to be construed as illustrative only and the invention isto be defined only by the terms of the appended claims.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. An electrolytic detector cell comprising;

(a) a housing having an apertured wall integrally formed therewith,

(b) a first pair of diaphragms secured to said housing on opposite sidesof said wall and together therewith defining a pair of compartments,

() an electrolytic detector solution filling said cornpartments,

(b) an orifice electrode disposed within the aperture in said wall andexternally connected to an electric circuit,

(e) a pair of electrodes, each electrode of said pair of electrodesbeing disposed within a respective one of said compartments andexternal-1y connected to said orifice electrode by an electrical biasingcircuit,

(f) a second pair of diaphragms,

(g) a first and second means respectively securing a respective one ofsaid second pair of diaphragms in spaced relationship with a respectiveone of said first pair of diaphragms and together therewith defining apair of chambers, one of said chambers disposed externally of arespective one of said pair of compartments and,

(h) an oxygen scavenging compound filling each of said pair of chambersto absorb any oxygen that would tend to diffuse through said second pairof diaphragms to prevent diffusion of any oxygen through said first pairof diaphragms and poisoning of the electrolytic detector solution.

2. An electrolytic detector cell comprising;

(a) a housing,

(b) a first pair of diaphragms closing the exterior portion of saidhousing, said diaphragms being normally exposed to the ambientenvironment of the detector cell,

(c) an oxidation-reduction solution substantially filling said housing,

(:1) a plurality of exteriorly connected electrodes disposed in saidsolution and together therewith providing an electrolytic detector cell,

(6) an orifice electrode disposed Within said housing between saidelectrodes and electrically coupled thereto exteriorly of said housing,

(f) means disposed between said plurality of electrodes and supportingsaid orifice electrode within said housing,

(g) a second pair of diaphragms,

(h) first and second means respectively securing a respective one ofsaid second pair of diaphragms in spaced relationship with a respectiveone of said first pair of diaphragms and together therewith forming apair of chambers and (i) a liquid containing oxygen getter compoundsubstantially filling each of said chambers whereby the oxygen gettercompound in said chambers '4 protects the oxidation-reduction solutionin said housing from oxidation by the ambient environment.

3. An electrolytic detector cell comprising:

(a) a housing,

(b) a pair of compartments disposed within said hous- (c) means disposedwithin said housing and separating said pair of compartments,

(d) orifice electrode means supported by the compartment separatingmeans,

(e) a pair of electrodes disposed one each in said compartments, saidelectrodes being of opposite polarity to said orifice electrode means,

(1) an oxidation-reduction electrolytic fluid substantially filling saidcompartments, said fluid having the property of being poisoned byoxygen,

(g) a pair of diaphragms each disposed about a respective compartmentfor closure thereof,

(12) a second pair of diaphragms,

(i) first and second means respectively securing a respective one ofsaid second pair of diaphragms in spaced relationship with a respectiveone of said first pair of diaphragms and together therewith defining afluid chamber on the outside of each of said pair of diaphragms and (1')a liquid including an oxygen scavenging compound substantially fillingeach of said chambers to prevent poisoning of the oxidation-reductionelectrolytic fluid by ambient oxygen.

4. An electrolytic detector cell comprising;

(a) a relatively thick-walled housing,

(b) an internal aperture wall aflixed to said housing;-

(c) an orifice electrode disposed within said aperture,

(d) a first pair of relatively thin diaphragms disposed at opposite endsof said housing and together with said apertured wall defining a pair ofelectrolytic compartments having said thin diaphragms as their outwardwalls,

(e) an oxidation-reduction electrolytic fluid filling said compartments,

(7) a pair of electrodes each disposed within a respective one of saidcompartments,

(g) external circuit means for biasing said last-named electrodes withrespect to said orifice electrode and for connecting said electrodes tosaid orifice electrode,

(h) a second pair of diaphragms,

(Z) first and second means respectively securing a respective one ofsaid second pair of diaphragms in spaced relationship with a respectiveone of said first pair of diaphragms and together therewith defining apair of chambers outwar ly adjacent to said first pair of diaphragms and(j) a quantity of oxygen scavenging liquid disposed within said chambersfor absorbing oxygen that would normally diffuse through said first pairof dia phragms into the electrolytic solution and for hydraulicallyconnecting said second pair of diaphragms with said first pair ofdiaphragms.

References Cited in the file of this patent UNITED STATES PATENTS2,464,799 Harry et a1 July 30, 1946 2,495,209 Harry Aug. 6, 19462,405,210 Inglis Aug. 6, 1946 2,615,940 Williams Oct. 28, 1952 2,685,025Root July 27, 1954 2,782,394 Hardway Feb. 9, 1957- 2,824,292 ChristophFeb. 18, 1958'.

OTHER REFERENCE5 Solions, Machine Design; vol. 29, Aug. 22, 1957,, pp.102105.

1. AN ELECTROLYTIC DETECTOR CELL COMPRISING; (A) A HOUSING HAVING ANAPERTURED WALL INTEGRALLY FORMED THEREWITH, (B) A FIRST PAIR OFDIAPHRAGMS SECURED TO SAID HOUSING ON OPPOSITE SIDES OF SAID WALL ANDTOGETHER THEREWITH DEFINING A PAIR OF COMPARTMENTS, (C) AN ELECTROLYTICDETECTOR SOLUTION FILLING SAID COMPARTMENTS, (D) AN ORIFICE ELECTRODEDISPOSED WITHIN THE APERTURE IN SAID WALL AND EXTERNALLY CONNECTED TO ANELECTRIC CIRCUIT, (E) A PAIR OF ELECTRODES, EACH ELECTRODE OF SAID PAIROF ELECTRODES BEING DISPOSED WITHIN A RESPECTIVE ONE OF SAIDCOMPARTMENTS AND EXTERNALLY CONNECTED TO SAID ORIFICE ELECTRODE BY ANELECTRICAL BIASING CIRCUIT, (F) A SECOND PAIR OF DIAPHRAGMS, (G) A FIRSTAND SECOND MEANS RESPECTIVELY SECURING A RESPECTIVE ONE OF SAID SECONDPAIR OF DIAPHRAGMS IN SPACED RELATIONSHIP WITH A RESPECTIVE ONE OF SAIDFIRST PAIR OF DIAPHRAGMS AND TOGETHER THEREWITH DEFINING A PAIR OFCHAMBERS, ONE OF SAID CHAMBERS DISPOSED EXTERNALLY OF A RESPECTIVE ONEOF SAID PAIR OF COMPARTMENTS AND, (H) AN OXYGEN SCAVENGING COMPOUNDFILLING EACH OF SAID PAIR OF CHAMBERS TO ABSORB ANY OXYGEN THAT WOULDTEND TO DIFFUSE THROUGH SAID SECOND PAIR OF DIAPHRAGMS TO PREVENTDIFFUSION OF ANY OXYGEN THROUGH SAID FIRST PAIR OF DIAPHRAGMS ANDPOSIONING OF THE ELECTROLYTIC DETECTOR SOLUTION.